The marine dinoflagellate genusAlexandriumincludes a number of species which produce neurotoxins responsible for paralytic shellfish poisoning (PSP), which in humans may cause muscular paralysis, neurological symptoms, and, in extreme cases, death.A. minutumis the most widespread toxic PSP species in the western Mediterranean basin. The monitoring of coastal waters for the presence of harmful algae also normally involves microscopic examinations of phytoplankton populations. These procedures are time consuming and require a great deal of taxonomic experience, thus limiting the number of specimens that can be analyzed. Because of the genetic diversity of different genera and species, molecular tools may also help to detect the presence of target microorganisms in marine field samples. In this study, we developed a real-time PCR-based assay for rapid detection of all toxic species of theAlexandriumgenus in both fixative-preserved environmental samples and cultures. Moreover, we developed a real-time quantitative PCR assay for the quantification ofA. minutumcells in seawater samples.Alexandriumgenus-specific primers were designed on the 5.8S rDNA region. Primer specificity was confirmed by using BLAST and by amplification of a representative sample of the DNA of other dinoflagellates and diatoms. Using a standard curve constructed with a plasmid containing the ITS1-5.8S-ITS2A. minutumsequence and culturedA. minutumcells, we determined the absolute number of 5.8S rDNA copies per cell. Consequently, after quantification of 5.8S rDNA copies in samples containingA. minutumcells, we were also able to estimate the number of cells. Several fixedA. minutumbloom sea samples from Arenys Harbor (Catalan Coast, Spain) were analyzed using this method, and quantification results were compared with standard microscopy counting methods. The two methods gave comparable results, confirming that real-time PCR could be a valid, fast alternative procedure for the detection and quantification of target phytoplankton species during coastal water monitoring.

A systematic sampling programme was carried out in a large number of confined waters (principally harbours) along the Catalan coast (NW Mediterranean) in the context of a new Monitoring Programme. This Monitoring Programme was associated not only with areas subject to aquaculture activities, and therefore under legislation, but also with confined areas with a high risk of harmful algal blooms (HABs) occurrence, in order to provide an early warning of potentially widespread HABs. The systematic programme was performed weekly in summer and bi-monthly in winter for five years. The main results were: (i) the detection of many harmful species and the presence of high numbers of harmful dinoflagellates, mainly of the genera Alexandrium and Dinophysis; (ii) the detection of Alexandrium catenella, new in the study area, which had hardly ever been detected in the Mediterranean Sea; (iii) the presence of some potentially harmful species, including Dinophysis sacculus, present at all periods of the year; (iv) bloom recurrence in several stations; (v) occasional coincidence of small-scale blooms, such as those confined inside the harbours, with widespread blooms (mesoscale blooms) of the same organism. The implications of this high frequency of HAB detection is discussed in relation to the suitability of this sampling programme (focused on confined waters) for the early detection of algal blooms.

Special issue on International Cooperation in Harmful Algal Bloom Science.-- 10 pages, 4 figuresShallow, well-illuminated coastal waters from tropical to temperate latitudes are attractive environments for humans. Beaches and coral reefs have provided lodging and food to coastal communities for centuries. Unfortunately, tropical regions traditionally have been threatened by outbreaks of the toxic benthic dinoflagellate Gambierdiscus, which is associated with ciguatera fish poisoning. The ciguatoxins produced by Gambierdiscus bioaccumulate in reef fishes and are responsible for the most common algal toxin-related illnesses, globally affecting the greatest number of victims and often with significant long-term health effects. Recently, Gambierdiscus has been documented in subtropical and temperate latitudes. Blooms of another benthic and toxic dinoflagellate, Ostreopsis, have become more frequent and intense, especially in temperate waters. Ostreopsis produces palytoxins and analogues, and some outbreaks have been associated with massive benthic faunal damage and respiratory irritations in humans exposed to aerosols. The increased frequency of harmful events and the biogeographic extension of benthic microalgae incentivized the launch of the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Core Research Project on “Benthic Harmful Algal Blooms” in 2010. This article summarizes the main scientific advances and gaps in related knowledge as well as advances the project has made toward managing and mitigating the impacts of benthic HABs on human illnesses and marine resource lossesThe authors, on behalf of the international community working on benthic HABs, thank the Intergovernmental Oceanographic Commission (IOC) of UNESCO and the Scientific Committee on Oceanic Research (SCOR) for their financial and logistic support for the launch and implementation of the GEOHAB CRP Harmful Algal Blooms in Benthic Systems program. The authors received further support from the National Oceanic and Atmospheric Administration (NOAA), the Contrat de Projets État-Pays of French Polynesia and the National French Project ANR OCEAN 2015, the International Atomic Energy Agency (IAEA), the Spanish funded projects OstreoRisk (CTM2014-53818-R) and CICAN (CGL2013-40671-R), the M3-HABs Project (ENPI CBC MED Programme, European Commission), the YEOSU project funded by the government of the Republic of Korea, grant DIP-2012-023 from the Universiti Kebangsaan Malaysia, and the “Ostreopsis Project” granted by the Assessorato alla Sanità of the Campania Region (Italy)Peer Reviewe